There was a recent post on the forums that asked if it was okay to run two instances of The Elder Scrolls Online, without third-party applications to control both. For example, park account two near account one to facilitate using banker, trading, etc.
While this may be a little clunky and could result in some PC slow-down, the general idea is fine. Now that said, if we find that someone is doing this as a means to violate our EULA or other Terms of Service rules in other ways, we may deem it actionable.ZOS_JessicaFolsom
Read the full post here.